This is a continuation-in-part of application Ser. No. 8,616, filed Jan. 29, 1987, and now abandoned.
This invention relates to a steering column switch. German OS No. 3,211,672 teaches a steering column switch for motor vehicles including a wiper-washer-switch and a turn-signal and headlamp beam control switch. The two individual switches have both a switch lever, onto which a ring-shaped switching member is integrally formed. The switching member extends around the steering spindle. Each switching member is swivellably mounted about a swivelling shaft extending in parallel to the steering spindle shaft and penetrating the switching member. By swivelling the switch lever the wiper operations can be started and terminated and lane changes can be indicated by the turn-signal and headlamp beam control switch. A washing operation can be initiated by tilting the wiper-washer-switch. By tilting the turn-signal and headlamp beam control switch the headlamp flasher can be operated and the headlamp beam can be changed over. The switching member may be secured in the various operating positions by means of several locking members. For this purpose a serrated locking cam is worked into the wiper-washer-switching member at a position approximately diametrically opposite the swivelling axis, in which locking cam engages by means of a triangular locking lug either integrally formed with the switch lever or formed as a separate part a spring-loaded locking lever swivellably mounted about a shaft parallel to the steering spindle shaft.
Because of the two-part guide construction taught on German OS No. 3,211,672 an undesired noise development has to be feared as early as in the rest condition of the switches. The insulation plates therein extend at a spacing from the switching member due to unavoidable tolerances. Thus, the switching member can inadvertently be tilted relative to the swivelling plane by vibrations occurring in the course of the driving movements of the motor vehicle and strike an insulation plate to cause a striking noise to appear. Also, due to the tolerances, the relatively long switch lever can additionally undergo undesired tilting motions about its longitudinal shaft when the switching member is moved into the various switching positions so that the switching member can also strike the insulation plates causing a striking noise to occur. Furthermore, the switching security can be impeded thereby.
A wiper-washer-switch substantially having the same construction as the steering column switch according to the German OS No. 3,211,672 is known from the U.S. Pat. No. 4,414,442. The switching member of this steering column switch has an L-shaped projection protruding beyond the underside of the switching member so that a groove is formed. A tongue engages in this groove, which tongue is formed onto an insulation plate. In principle, a good guide of the switching member and of the switch lever is, thus, possible in the swivelling plane. However, it is a disadvantage of the steering column switch according to the U.S. Pat. No. 4,414,442 that the L-shaped projection and the tongue require additional space below the switching member.